In electrophotography or other techniques so far known in the art, a photoconductive layer is vapor deposited on an electrode layer. After the photoconductive layer is electrically charged all over the surface, "image exposure" is carried out to cause some charges to leak out of the exposed region, thereby forming optically an electrostatic latent image thereon. A toner opposite in polarity to the residual charges is then deposited on the latent image, which is in turn electrostatically transferred onto paper, etc. for development. According to these techniques which are mainly used for copying, the period of carrying electrostatic charges in the photoconductive layer serving as a recording medium is so reduced that toner development must be conducted just after the formation of the electrostatic latent image. Thus, they can never be used for, e.g. photographing because of their low sensitivity.
With TV photographing techniques, it is required to extract electrical image signals obtained in a pick-up tube and subjecting the resulting image to sequential line scanning for recording. Sequential line scanning is conducted with electron beams in the pick-up tube and with a magnetic head in the case of video recording. However, a problem with these techniques is that the resolution, depending upon the number of scanning lines, is much lower than that achieved with planar analog recording such as silver photography.
This is also essentially true of recently developed TV image pickup systems making use of solid-state image sensors. A problem associated with these techniques are that the higher the quality and resolution of image recording, the more complicated the processing steps involved, or the more simplified the processing steps, the more likely it is that some memory function is lost or the quality of images degrades seriously.
This invention has for its object to improve the capability of an electrostatic information-recording medium to carry electrostatic information, and seeks to provide an electrostatic information-recording medium improved in terms of the capability to carry electrostatic information and a process for recording and reproducing electrostatic information with such a recording medium.